The voodoo octave is a cheap octazver/fuzz pedal made by Joyo. Fuzz, tone and volume knobs are pretty common, but there is a little mid cut switch to get a "Muffer" tone and a fat sound. There's also 2 footswitches : on/off and octave, which make it more polyvalent. Personally I don't hear a "real fuzz" like Fuzz Face or Maestro, it's more a high distorsion. Basically, it permits to get 4 different kind of tone : classical or mid-cut and both avaible with or without octave up ! And i won't talk about variations with the fuzz knob, that's pretty effective. The octave sound can't be activated without fuzz and adds an octave up. A famous sound heard in Hendrix or Neil Young's records, for simple riffs or legendary solos, but don't try with too complex chords or it will turn into a real mash !!
To conclude it's a good product if you want to test the octafuzz tone at a low price unlike vintage reissues (and even more with only vintage ones), however it will necessarily need to be replaced. It's a nice stuff to begin, but a bit too 'cold' compared to vintage records.
(A little trick if you find it a bit too "synthetical" as i said : try to set a vintage drive before or after on in order to get a warmer sound ;)